GML coordinates from vector layer

Question

Is it possible to get GML from a local vector layer (OpenLayers.Layer.Vector)?

What I would like to do is use the output geometry from my buffer tool to spatially limit a WPS gs:Aggregate request using a WFS/OGC filter. I am not sure if it is even possible (and there might very well be a better solution), but I would still be interested in knowing if it is possible to derive GML coordinates from a vector layer. I’m running the Boundless OpenGeo Suite (GeoServer).

Answer 1

I managed to get the geometry to GML-format by reading these two question: First and second.

Code:

featureadded: function (event) {

 var geometry = event.feature.geometry;

 var gml = new OpenLayers.Format.GML(); 

 var polygonGML = gml.buildGeometry.polygon.apply(gml,[feature.geometry])     
 var plgGMLString = (new XMLSerializer()).serializeToString(polygonGML);

 ...

 }

Answer 2

I think it is easier to make a WFS request in your browser (no need to involve OpenLayers):

http://192.168.154.7:8090/geoserver/wfs?
service=wfs&
version=2.0.0&
request=GetPropertyValue&
typeNames=workspace_name:vector_layer_name&
valueReference=geom&
outputFormat=gml2

You'll obtain something like this:

<wfs:member>
  <ACGL:geom>
    <gml:Polygon srsDimension="2" srsName="urn:ogc:def:crs:EPSG::31700">
      <gml:exterior>
        <gml:LinearRing>
          <gml:posList>
            473502.3205767908 693338.8402676274
            473412.06868474645 693167.3616708852
            473428.66570708115 693159.2152727067
            473513.17858519114 693333.7602303769
            473502.3205767908 693338.8402676274
          </gml:posList>
        </gml:LinearRing>
      </gml:exterior>
    </gml:Polygon>
  </ACGL:geom>
</wfs:member>

Read more here.